Foams are typically made of organic polymers, such as polyurethane, and are widely used as thermal insulating building materials, adhesives, cellular scaffolding for bone regeneration, and for acoustical vibration control. Conductive polyurethane foams are also known.
Conductive polyurethane foams are prepared in various ways. For example, metal ion salts or conductive solid fillers, such as carbon or metals, can be added to the foam formulation, or conductive polyurethane foams can be made by imbibing the foam with a solvent containing a conductive material. A polyurethane foam can also be coated with a conductive material to form a conductive foam. More recently, U.S. Patent Application Publication No. 2008/0073622 has described conductive polyurethane foams that are produced using a foam formulation and a conductive component that has at least one organic compound, such as an ionic liquid, at least one metal salt and/or combinations thereof.
Foamable poly(ionic liquids) bearing tert-butyl ester groups that are microwave sensitive have been prepared by Amajjahe et al as described in Macromol. Rapid Commun. 30:94-98, 2009.
Although polyurethane provide a foam with useful properties, a need remains for ionic foams, which would be useful for many additional applications such as catalysis, separations, gas storage, biosensors, electronic and electrochemical applications.